1. Technical Field
This invention relates generally to seal assemblies, and more particularly to rotary shaft seal assemblies.
2. Related Art
Shaft seals are commonly used throughout numerous types of vehicle applications. Aside from the shaft seal establishing a reliable seal against a running surface of a rotating shaft or wear sleeve, both to prevent the ingress of contamination and the egress of desirable lubrication, it is desirable that the seal provide a minimal running torque against the shaft. A reduced running torque of the seal helps to enhance the overall fuel economy of the vehicle, as lower torque requires less parasitic horse power to turn the shaft, such as a crankshaft, for example, due to less drag produced by the shaft seal against the running surface of the shaft. Unfortunately, compromises are generally necessary in order to accomplish either a maximized seal or minimized friction with the shaft. Further, it is also desirable that the seal lip be easily and properly installed onto the shaft. Unfortunately, sometimes the seal lip becomes unknowingly inverted during installation, thereby resulting in problems in use.
A shaft seal constructed in accordance with the subject invention addresses the need to accomplish both a reliable seal and minimized friction, while also being readily installable on a shaft in an air-side installation without concern of inadvertent seal lip inversion.